One of the major challenges with introducing mass wind- and solar-generated electricity is that nobody can be sure when the wind will blow and the sun shine. So the electrical grid needs a way to store power from peak-generation hours for use when there’s less being churned out. Now a British scientist proposes a centralized system for coordinating millions of ordinary household water heaters: they would be switched on to store heat at peak production hours for use in showers or washing machines whenever needed. Don’t laugh: in New Zealand, Florida and South Africa, versions of the scheme have already proven highly effective.
When you can’t rely on the wind and the sun
Solving big energy problems with household hot-water tanks